Virucidal properties of metal oxide nanoparticles and their halogen adducts

Selected metal oxide nanoparticles are capable of strongly adsorbing large amounts of halogens (Cl2, Br, I2) and mixed halogens. These solid adducts are relatively stable thermally, and they can be stored for long periods. However, in the open environment, they are potent biocides. Herein are described studies with a number of bacteriophage MS2, φX174, and PRD-1 (virus examples). PRD-1 is generally more resistant to chemical disinfection, but in this paper it is shown to be very susceptible to selected interhalogen and iodine adducts of CeO2, Al2O3, and TiO2 nanoparticles. Overall, the halogen adducts of TiO2 and Al2O3 were most effective. The mechanism of disinfection by these nanoparticles is not completely clear, but could include abrasive properties, as well as oxidative powers. A hypothesis that nanoparticles damage virons or stick to them and prevent binding to the host cell is a consideration that needs to be explored. Herein are reported comparative biocidal activities of a series of adducts and electron microscope images of before and after treatment.